Optical disc playback apparatus and method which utilizes single RAM for data decoding and TOC processing

Abstract

An optical disc playback apparatus for playing back information such as music recorded on a compact disc (CD) and/or information such as data recorded on compact disc read only memory (CD-ROM) comprises: device for reading the information from the CD or the CD-ROM; device for decoding the CD-ROM data from the reading device; device for processing TOC information from the reading device; memory for storing CD TOC information when the CD is played back, and data to be used for decoding the information recorded on the CD-ROM when the CD-ROM is played back; and device for changing over between using the memory for storing the TOC information or using the memory as a data decoder for the CD-ROM.

What is claimed is: 
     
       1. An optical disc playback apparatus for playing back information such as music recorded on a compact disc (CD) and/or information such as data recorded on compact disc read only memory (CD-ROM) comprising: means for reading the information from the CD or the CD-ROM;   means for decoding the CD-ROM data from said reading means;   means for processing TOC information from said reading means;   storing means for storing CD TOC information when the CD is played back, and, alternatively, for storing data to be used for decoding the information recorded on the CD-ROM when the CD-ROM is played back; and   means for changing over between using said storing means for storing the TOC information or using said storing means as a data decoder for the CD-ROM.   
     
     
       2. An optical disc playback apparatus according to claim 1, wherein said storing means is a random access memory (RAM). 
     
     
       3. An optical disc playback method for playing back information such as music recorded on a compact disc (CD) and/or information such as data recorded on a compact disc read only memory (CD-ROM) comprising the steps of: storing TOC information recorded on the CD-ROM in a storage means when the CD-ROM is first loaded into the apparatus; and   detecting from data read from the disc whether the disc is a CD or a CD-ROM and, if the disc is a CD-ROM, ignoring the TOC information stored in said storage means and connecting the storage means from a microcomputer controller over to a CD-ROM data decoder supplied with data read from the disc while the loaded CD-ROM is being played back and storing decoded CD-ROM data in the storage means.   
     
     
       4. An optical disc playback method according to claim 3, wherein the step of storing the TOC information or the decoded CD-ROM data comprises storing such TOC information or decoded CD-ROM data in a random access memory (RAM). 
     
     
       5. An optical disc playback apparatus for playing back information from a disc, such as music recorded on a compact disc (CD) or information such as data recorded on a compact disc read only memory (CD-ROM), comprising: reading means for reading the information from the disc;   data decoding means for decoding CD-ROM data from the reading means;   a microcomputer connected to the data decoding means and the reading means for processing TOC information from the reading means and for detecting from the information read by the reading means whether the disc is a CD or a CD-ROM;   memory means connected to the microcomputer for initially storing the TOC information when the CD is played back, and, alternatively, connected to the data decoding means for storing data to be used for decoding the information recorded on the CD-ROM when the CD-ROM is played back; and   switching means controlled by the microcomputer for alternatively connecting the memory means to the microcomputer, for storing the TOC information, or to the data decoding means for storing decoded CD-ROM data.   
     
     
       6. An optical disc playback apparatus according to claim 5, wherein the memory means is a random access memory (RAM). 
     
     
       7. An optical disc playback method for playing back information from a disc, such as music recorded on a compact disc (CD) or information such as data recorded on a compact disc read only memory (CD-ROM), comprising the steps of: initially reproducing TOC information recorded on the disc and storing the TOC information in a storage means when the disc is first loaded into the apparatus; and   detecting from data read from the disc whether the disc is a CD or a CD-ROM and, if the disc is a CD-ROM, disregarding the TOC information stored in the storage means and connecting the storage means from a microcomputer controller over to a CD-ROM data decoder supplied with data read from the disc, while the loaded CD-ROM is being played back, and storing decoded CD-ROM data from the CD-ROM data decoder in the storage means.   
     
     
       8. An optical disc playback method according to claim 7, further comprising the step of reading the TOC information from the storage means when it is detected that the disc is a CD. 
     
     
       9. An optical disc playback method according to claim 7, further comprising the step of reading TOC information from the disc, rather than from the storage means, after it is detected that the disc is a CD-ROM.